Frictional contact analysis and experiment study of complex mechanism with pinned connections

Hybrid mode aerial working vehicle (HMAWV) is a complex mechanism with many pinned connections, so it is unrealistic to get a good strength analysis by analytical method. Two numerical methods, dynamic simulation of flexible multibody systems and contact element method in FEA were developed. Contact elements including friction were discussed in depth based on a simply supported beam, and the effects of contact parameters on distribution of contact stress and global stress were analyzed by response surface method. It indicated that frictional coefficient and contact stiffness could influence distributions of contact stress tremendously, but had a trivial effect on global stress; additionally these three parameters had an important effect on the convergence of nonlinear contact analysis. Subsequently the contact element method was applied to HMAWV. In order to get a more reliable result, experimental studies were carried out. Passive strain gauges were applied to test the stresses, and then the results of tests were compared with the flexible multibody method and the contact element method. It was proved that the contact element method was more precise than the flexible multibody method under special cases. Moreover the relative error of the contact element method to experimental study was lower than 5%; therefore it had a good agreement with the experiment results.